A keyboard (e.g., wireless) can be used for remote operational control when the app is in Prompter mode. The "<" and ">" buttons decrease/increase prompter scroll speed by 0.1 increments. The up/down buttons will increase/decrease prompter scroll speed by a larger increment, settable in the Global Settings popover panel (default 0.5). Other controls can also be executed from the same keyboard. Note that these are NOT case sensitive. You do not have to press the "shift" key.
When in edit mode, the keyboard operates in normal mode. Note that you can enter script-edit mode from the remote keyboard, but currently there is no way to remotely go back to remote control of the prompter. This is an unfortunate limitation in Apple, Inc.'s iOS text handling, which does not allow access to raw key-clicks, such as "F" keys and modifier keys. We have filed a feature request with Apple, Inc. to address this issue.